1. Field of the Invention
The present invention relates to multilayer photographic photosensitive materials whereby image quality such as sharpness, graininess, exposure tolerance or color reproduction, etc. is improved and uniformity of finished quality at development is improved. Particularly, it relates to photographic photosensitive materials which do not exhibit development mottle or which do not result in an uneven finish on high temperature development.
2. Description of the Prior Art
It is known to use hydroquinone derivatives which release a development inhibitor at development in order to improve the image quality. For example, they are described in U.S. Pat. 3,379,529 as the so-called "IRD-Inhibitor Releasing Developers" or in U.S. Pat. No. 3,620,746, and Japanese Patent Applications 41870/1973 and 87723/1973 as the so-called "DIR-Hydroquinone-Development Inhibitor Releasing Hydroquinones". Hydroquinone derivatives which release a development accelerator at development have been used in order to provide a hard tone image or to accelerate image development. Further, they are used together with the so-called "DIR-compounds" such as "DIR-couplers" or "DIR-hydroquinones" in order to obtain excellent image quality.
In general, color photographic photosensitive materials comprise a blue sensitive emulsion layer containing a yellow coupler (BL), a green sensitive emulsion layer containing a magenta coupler (GL), a red sensitive emulsion layer containing a cyan coupler (RL), middle layers (ML), a filter layer which absorbs ultraviolet light or visual light of a specific wavelength (FL), an antihalation layer (AHL), a protective layer (PL) and a photosensitive emulsion layer prepared by varying the coupler and distribution of spectral sensitivity depending on the purpose, etc.
Particularly, in color photographic sensitive materials, many methods have been developed in order to improve color image quality, for example, color reproduction, color saturation, graininess of the color image and color sharpness, etc. For example, methods are described in Japanese Patent Application 33238/1973, 41870/1973 and 50051/1973, etc. "Interlayer Color Correction Hydroquinone Derivatives" defined in Japanese Patent Application 87723/1973 are used.
However, when these methods are practiced, serious defects appear.
A first defect is as follows. Namely, the development inhibitor or accelerator which was released at development diffuses into an adjacent layer to cause an interlayer interimage effect or undercut interimage effect, however that contaminates the developer by exudation and changes its developing ability. Consequently, the final finished quality at development is not uniform.
A second defect is that a compound which was released at development diffuses into an adjacent layer, is absorbed into the developer and partially inhibits neighboring development to cause development mottle. It is also known that iodine ions released at development exhibit an interlayer inter image effect and that the iodine ions are completely trapped by adjacent silver halide particles. It is also known that iodine ions cause an exchange reaction with silver bromide or silver chloride for red development. A third defect is that development mottle caused by "DIR-hydroquinone derivatives" is easily formed using a rapid developing treatment at a temperature higher than 30.degree.C.